1. Field of the Invention
The present invention relates to a method for orienting well casing and other tubular work objects and a device therefor and more particularly to such a method and device having particular utility when employed in conjunction with the method and well casing of the applicant's copending patent application Ser. No. 282,395, filed July 13, 1981, now U.S. Pat. No. 4,382,470.
As set forth in the applicant's aforementioned copending patent application Ser. No. 282,395, filed July 13, 1981, the disclosure of which is herein incorporated by reference, the invention of that application affords the capability of maintaining well productivity at a high level while minimizing the energy requirements for maintaining such a level of production and permits fluid to be pumped from two or more fluid bearing formations simultaneously without modification or repositioning of the pump assembly and without risk of destruction of the pump assembly as a result of entrapped air. The method thereof may be characterized by establishing a pair of passages in communication with a fluid bearing formation and pumping fluid along the pair of passages as described and claimed therein. This is accomplished in the preferred embodiment of that application by the use of a double walled well casing constructed, in part, from a pair of substantially concentric walls, the outer one of which is perforated adjacent to its upper extremities to communicate with the formation and the inner one of which communicates with the formation at its lower end portion and with the interior of the outer wall below the perforations thereof.
2. Description of the Prior Art
Conventional techniques for orienting work objects and, in particular, for orienting conventional well casing are less than satisfactory when applied to the well casing of the applicant's aforementioned invention. Conventional practice in installing conventional well casing calls for the casing to be assembled in sections of twenty to forth foot lengths. A first section is supported in the borehole with its upper end portion at the earth surface. Thereafter, a second section is lowered using a crane and slipped into the collar of the upper end portion and welded in position. Subsequently, the two welded sections are lowered into the borehole until the upper end portion of the second section is at the earth surface. Succeeding sections of well casing are then successively positioned in their respective preceding sections, welded in position and lowered into the borehole until a casing of the length required has been assembled.
This method is not satisfactory in installing the double walled casing of the applicant's invention. Conventional techniques would require that the inner wall be mounted in position first and the outer wall then be suspended over the inner wall and moved downwardly thereabout and into position for mounting on its respective preceding section. Since the inner and outer walls may total in length from forty to eighty feet in the aggregate, it would be necessary to use quite heavy duty and very large equipment including a very tall crane to maneuver the outer wall over and then downwardly about the inner wall. This is both cumbersome in operation and quite expensive in view of the size of the equipment involved and the time and manpower required.
Therefore, the present invention is directed to providing an improved method and device for orienting well casing and other tubular work objects having particular utility in the installation of the well casing of the applicant's aforementioned invention.